Traditionally, a job meant a written contract between a person who works and a person who orders this work and gives money for it. Contract is made for a long time, determining the worker’s duties, salary and benefits. All of those were (and are often still) fixed, which means that the employee has to come to workplace at certain days and hours and gets the same amount each month or week, with occasional raises (permanent or for one time) for good work and decreases as a punsihment or due to lesser profits. Only in enterprises owned by workers they regularly got the profits so their earnings depended much more on their effort – and luck, too.
In modern times, people swap employers and even occupations more often. This is in part due to frequent bankrupcies and corporations’ owners’ desire to save money they would use for salaries and insurances, both of which destroy some people’s previous livelihoods and force them to seek another one; but more than before also leave the previous employer voluntarily to find a kind of work that will give them more satisfaction. This does often not mean just higher salaries but also more free time, more flexible schedules or something that they will enjoy and will give more to others.
Modern employment allows more flexibility. In some enterprises, workers can leave when they are done with the day’s tasks instead of strictly following the schedule. On the other hand, there are still employers who insist they stay at the workplace until the time determined even if they have nothing to do and some legislations require it for workers that are paid with taxpayers’ money.
Some workers even have no schedules and are required to have their telephone always switched on and near them so they can be called to workplace whenever needed. They cannot know whether this will be forenoon, afternoon or night. This makes it even harder to balance work and life.